Although there are age limits on gambling throughout the United States, research consistently shows that adolescents and young adults are significantly more likely to be characterized as problem gamblers than their adult counterparts. Youthful gambling is also significantly correlated with other adolescent problem behaviors including alcohol, other substance use and delinquency. However, there is very little research on the etiology of adolescent gambling and there are no longitudinal studies examining the development of youthful gambling behaviors in the context of substance use. Cost-effective secondary data analysis is proposed using two longitudinal studies previously funded by NIAAA to focus on adolescent alcohol misuse. Both studies include the same measures of gambling behaviors. The gambling measures have not been analyzed due to limited resources. Study 1 (Family and Adolescent Study), is a six-wave longitudinal panel study of 699 adolescents, aged 13-16 at wave 1 and 18-23 at wave 6 with independent assessments from parents and peers. Study 2 (Delinquency in Young Men) is a three-wave longitudinal panel study of substance use and delinquency among 625 males, aged 16-19 at wave 1 and 19-22 in wave 3 with an independent assessment from a family respondent (usually the mother). Both studies employed general population samples; but Study 1 included an oversample of black families and Study 2 included an oversample of young men at high risk for delinquency. Using a conceptual model of the development of the co-occurrence of gambling, substance use and delinquency, cross-sectional and longitudinal analyses are specified using predictors from sociodemographic, individual/psychological, and parent/peer socialization domains. The specific aims are to determine: a) the sociodemographic correlates of gambling behaviors; b) the relationships between individual/psychological factors and gambling; c) the family and peer influences on the development of gambling behaviors and d) the inter-relationships between gambling, alcohol and other substance use and delinquency as well to examine the common etiological factors influencing these problem behaviors. A better understanding of the protective and risk factors for youthful gambling can be used to inform prevention strategies.